United States Environmental Protection Agency Transportation and Air Quality Transportation and Regional Programs Division EPA420-F-00-037 March 2002 www.epa.gov SUCCESS STOfty Georgetown University in Washington, DC, has successfully developed a fuel cell that uses methanol—a fuel derived from renewable sources and readily available at a reasonable price. Grant- ed money in 1991 from the U.S. Federal Transit Admin- istration, Georgetown has actively researched using fuel cells in transit buses. The university has proposed building eight fuel cell-pow- ered transit buses for research and testing. Through this program, Georgetown has learned valuable information about fuel cell technology's perfor- mance and promise. The university's research will play an important role in the future commercialization of fuel cell technology for vehi- cles. For more information, contact James Larkins, Georgetown's program manager, at (202) 687- 7361. Clean Fuels: Fuel Cells One in a series of fact sheets From midsize passenger vehicles to large transit bus fleets, fuel cells offer a promising new source of clean power for electric vehi- cles. This innovative technology uses chemical energy rather than combustion to generate electric power, resulting in far fewer emissions. In addition, fuel cell vehicles can utilize renewable fuel and are expected to pro- vide a wider driving range than today's battery-powered electric vehicles. At least seven types of fuel cells are currently being researched (see box). Fuel cells generate power through an elec- trochemical process, much like a battery. They convert chemical energy to electrical energy by combining hydrogen from fuel with oxygen from the air. Hydrogen fuel can be supplied in two ways—either directly as pure hydrogen gas or through a "fuel reformer" that converts hydrocarbon fuels such as methanol, natural gas, or gasoline into hydrogen-rich gas. AVAILABILITY Three major U.S. manufacturers and sev- eral European and Japanese manufacturers are actively researching fuel cell trans- portation technologies and testing proto- type passenger vehicles. Several North American cities are also testing fuel cell- powered transit buses. There are no fuel cell vehicles currently available for sale in the United States, but one major U.S. automaker has announced plans to make 40,000 fuel cell vehicles available for pur- chase by the general public by 2004. At least four other manufacturers also plan to market fuel cell vehicles that year. Providing fuel to power these vehicles presents several challenges. Large invest- ments are required to establish hydrogen production facilities and a convenient hydrogen distribution system to serve the general public. As an alternative, manufac- turers are working to improve fuel reform- ers to allow fuel cell vehicles to use conventional fuels, which would encourage consumer acceptance of this technology. EMISSIONS CHARACTERIST |CS* * R Actual emissions will vary wi engine design. • Fuel cell vehicles operating on hydrogen or methanol can achieve zero emission vehicle levels. • Fuel cells operating with a fuel reformer emit water vapor, carbon dioxide, and hydrocarbon emissions. * Estimates based on fuel cell's inherently "cleaner" properties. ------- AFFORDABILITY There is no data currently available on fuel cell vehicle costs because the vehicles are not yet commercially available. Vehicle costs are expected to vary depending on the fuel cell technology used and the scale of vehicle production. Fuel prices also will vary. Though hydrogen derived from natural gas is more expensive than conventional fuels, vehicles fueled by hydrogen achieve greater fuel economy. Keys to making these vehicles cost-competitive include providing low-cost, high-volume manufacturing processes, as well as lightweight, compact, and affordable hydrogen storage systems. PERFORMANCE Because the technology is still under development, fuel cell vehicles' per- formance has not been well-studied or documented. Based on available research, fuel cell vehicles are expect- ed to offer an extremely quiet ride with little vibration. Compared with conventional vehicles, fuel cell vehi- cles are also expected to provide improved fuel economy, increased engine efficiency, lower smog- forming emissions, and reduced greenhouse gas emissions. SAFETY Safety issues vary depending on the specific fuel source used. Although most fuel cells, fuel reformers, and fuel storage systems are not heavier than conventional systems, some may be. For such systems, the added weight can make stopping the vehicle more difficult. The onboard fuel reformers also present unique safety concerns—some reformers can gen- erate internal temperatures up to 1,000°C and produce steam or steam fuel mixtures at very high pressures. For More Information EPA Alternative Fuels Web Site www.epa.gov/otaq/ consumer/fuels/altfuels/ altfuels.htm Fuel Cell Institute P.O. Box 65481 Washington, DC 20035 Phone:301681-3532 Fax:301681-4896 Alternative Fuels Data Center Web site: www.afdc.nrel.gov National Alternative Fuels Hotline Phone: 800 423-1 DOE Types of Fuel Cells All fuel cells contain two electrodes—one positively and one negatively charged—with a substance that conducts electricity (electrolyte) sandwiched between them. Fuel cells can achieve 40 to 70 percent efficiency, which is sub- stantially greater than the 30 percent efficiency of the most efficient internal combustion engines. The following are different types of fuel cells: • Phosphoric Acid—The most commercially developed fuel cell, generates electricity at more than 40 percent efficiency. • Proton Exchange Membrane—Considered the leading fuel cell type for passenger car applications, operates at relatively low temperatures and a high power density. • Molten Carbonate—Promises high fuel-to-electricity efficiencies and the ability to utilize coal-based fuels. • Solid Oxide—Can reach 60 percent power-generating efficiencies and be employed for large, high-powered applications such as industrial generating stations. • Alkaline—Used extensively by the space program, can achieve 70 percent power-generating efficiencies, but is considered too costly for transportation applications. • Direct Methanol—Expected efficiencies of 40 percent with low operating temperatures; able to use hydrogen from methanol without a reformer. • Regenerative—Currently being researched by NASA; closed loop form of power generation that uses solar energy to separate water into hydrogen and oxygen. 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